Superconducting power transforming apparatus

ABSTRACT

The present invention relates to a superconducting power transforming apparatus. The superconducting power transforming apparatus according to the present invention comprises a transformer housing having a transforming cable passing hole and filled with a liquid cooling means; a superconducting transformer housed in the transformer housing in a state that the superconducting transformer is immersed in the liquid cooling means; a tap changer housing having a tap changing cable passing hole and vacuum-sealed from outside; a power tap changer housed in the vacuum tap changer housing; and a cable linking pipe vacuum-sealed from the transformer housing and the tap changer housing, and linking the transforming cable passing hole with the tap changing passing hole in order that a transformer winding tap cable connecting the superconducting transformer and the power tap changer passes through. Consequently, it is possible to guarantee stable operation of a superconducting transformer which works at an extremely low temperature and a power tap changer as like On-Load Tap Changer which works at low temperature.

TECHNICAL FIELD

The present invention relates to a superconducting power transformingapparatus, and more particularly to the superconducting powertransforming apparatus for guaranteeing stable operation of asuperconducting transformer which works at an extremely low temperatureand a power tap changer such as On-Load Tap Changer which works at lowtemperature or in an insulating oil.

BACKGROUND ART

Generally, a transformer is a device that changes AC voltage or DCvoltage using the effect of electro-magnetic induction. A powertransformer connected to a usual power transmission and distributionline comprises a primary winding connected to a power supply and asecondary winding connected to a load, and changes a voltage to a higheror lower voltage without changing a power.

And, various researches have been conducted on the development of thesuperconducting power device without resistance loss, since asuperconductor had been developed. The development of the hightemperature superconductor (HTS) overcoming the limitation of the lowtemperature superconductor which can work at an extremely lowtemperature has accelerated the research for the practical use of thesuperconducting power device, and the research for the practical use ofthe superconducting transformer using a superconductor (hereinafter,“the superconducting power transforming apparatus”) has been continued.

The superconducting power transforming apparatus has the merit of beingsmall, light, highly efficient, environment-friendly andoverload-resistant by comparison with usual transformer.

At an early stage of researches about the superconducting powertransforming apparatus, it was recognized as a principal merit of thesuperconducting power transforming apparatus to enable to save energyand reduce costs for operation by high efficiency.

However, recently, it is recognized as more principal merit to enable toreduce its weight and size.

A standard capacity of 3-phase 154 kV class transformer in general useis 60MVA, and that is installed and operated at a basement of a buildingin large cities.

As a load is increasing in the near future, the size of the existingtransformer using a cooper cable will increase as a consequence of thecapacity increase of that. The size increase of a transformer will raisethe problem that the existing transformer should be moved to more widespace.

Here, if the superconducting transformer will be substitute for theexisting transformer, the limitation of the installation spacecorresponding to the capacity increase will be solved through reducingits size by half or one third than the existing transformer.

Meanwhile, it is ideal that a secondary voltage (load voltage or lowtension) is maintained at a rated voltage in a transformer. But, becausea primary voltage is irregular at each installation place and theinternal voltage drop of a transformer is changed by the load currentintensity and the power factor, the problem occurs that a secondaryoutput voltage is fluctuated too. Therefore, on-load tap changer (OLTC)which adjusts the secondary voltage to the rated voltage by means of thechange of turns-ratio is installed and used in the transformer so as toadjust the secondary voltage to the rated voltage for the changing load.

The adjustment of the secondary voltage to the rated voltage is alsonecessary for the superconducting transformer. Therefore, on-load tapchanger (OLTC) which may be applied to the superconducting transformerhave to be considered for a practical use of the superconductingtransformer.

Generally, the existing transformer and on-load tap changer areinstalled and operated together while they are immersed in theinsulating oil.

However, even though the superconducting transformer is put to practicaluse, the problem occurs that the installation method of the existingtransformer and on-load tap changer can't be applied to thesuperconducting transformer. Namely, the “high” of the high temperaturesuperconducting transformer just means higher temperature than “low”temperature of the low temperature superconducting transformer. Becausethe high temperature superconducting transformer even works at extremelylow temperature which is much lower than the existing transformer does,the high temperature superconducting transformer can't works in a statethat it is immersed in the insulating oil with on-load tap changertogether.

DISCLOSURE Technical Problem

The present invention has been made in view of the above problems, andit is an object of the present invention to provide the superconductingpower transforming apparatus enabling a superconducting transformer anda power tap changer to work in a mutually independent operatingenvironment, in order to guarantee stable operation of a superconductingtransformer which works at an extremely low temperature and a power tapchanger such as On-Load Tap Changer which works at low temperature or inan insulating oil.

Technical Solution

In accordance with an aspect of the present invention, the above objectscan be accomplished by the provision of a superconducting powertransforming apparatus according to the present invention comprising atransformer housing having a transforming cable passing hole and filledwith a liquid cooling means; a superconducting transformer housed in thetransformer housing in a state that the superconducting transformer isimmersed in the liquid cooling means; a tap changer housing having a tapchanging cable passing hole and vacuum-sealed from outside; a power tapchanger housed in the vacuum tap changer housing; and a cable linkingpipe vacuum-sealed from the transformer housing and the tap changerhousing, and linking the transforming cable passing hole with the tapchanging passing hole in order that a transformer winding tap cableconnecting the superconducting transformer and the power tap changerpasses through.

Also, another aspect of the present invention is achieved by providing asuperconducting power transforming apparatus comprising a transformerhousing having a transforming cable passing hole and filled with aliquid cooling means; a superconducting transformer housed in thetransformer housing in a state that the superconducting transformer isimmersed in the cooling means; a tap changer housing having a tapchanger cable passing hole and filled with a insulating oil; a power tapchanger housed in the tap changer housing in a state that the power tapchanger is immersed in the insulating oil; and a cable linking pipevacuum-sealed from the transformer housing and the tap changer housingand linking the transforming cable passing hole with the tap changingpassing hole in order that a transformer winding tap cable connectingthe superconducting transformer and the power tap changer can passthrough.

Here, the superconducting transformer is provided with a type of a hightemperature superconducting transformer; and the liquid cooling meansare provided with liquid nitrogen.

Also, the power tap changer may be provided with a type of an On-LoadTab Changer (OLCT).

Here, the superconducting power transforming apparatus further comprisesa transforming coupling part coupled with the cable linking pipe andprovided on the transforming cable passing hole of the transformerhousing; and a tap changing coupling part coupled with the cable linkingpipe and provided on the tap changing cable passing hole of the tapchanger housing. Also, the cable linking pipe comprises a cylindricallinking pipe main body, a transforming connecting part provided on theone side of the linking pipe main body and sealingly coupled with thetransforming coupling part, and a tap changing connecting part providedon the other side of the linking pipe main body and sealingly coupledwith the tap changing coupling part.

And, the superconducting power transforming apparatus further comprisesa transforming sealing wall installed between the transforming couplingpart and the transforming connecting part, sealing the transformerhousing and the cable linking pipe and having a plurality of a firstcable passing holes where the transformer winding tap cable passes; anda tap changing sealing wall installed between the tap changing couplingpart and the tap changing connecting part, sealing the tap changerhousing and the cable linking pipe, and having a plurality of a secondcable passing holes where the transformer winding tap cable passes.

Here, the plurality of the first cable passing holes is spaced apartfrom each other at a predetermined distance in order to prevent aninsulation breakdown between the transformer winding tap cables passingthrough each of the first cable passing holes; and the plurality of thesecond cable passing holes is spaced apart from each other at apredetermined distance in order to prevent an insulation breakdownbetween the transformer winding tap cables passing through each of thesecond cable passing holes.

And, the transforming sealing wall and the tap changing sealing wall areprovided with epoxy resin.

Also, the cable linking pipe further comprises a pump connecting partconnected with a vacuum pump for making an inner of the linking pipemain body vacuous.

ADVANTAGEOUS EFFECTS

According to the present invention, the present invention can providethe superconducting power transforming apparatus enabling asuperconducting transformer and a power tap changer to work in amutually independent operating environment, in order to guarantee stableoperation of a superconducting transformer which works at an extremelylow temperature and a power tap changer such as On-Load Tap Changerwhich works at low temperature or in an insulating oil.

DESCRIPTION OF DRAWINGS

FIG. 1 is a view illustrating a constitution of the superconductingpower transforming apparatus according to the present invention;

FIG. 2 shows a coupling constitution of the transformer housing, thecable linking pipe and the tap changer housing of the superconductingpower transforming apparatus according to the present invention;

FIG. 3 shows a view illustrating a constitution of the transformingsealing wall of the superconducting power transforming apparatusaccording to the present invention.

BEST MODE FOR INVENTION

The present invention relates to a superconducting power transformingapparatus comprising a transformer housing having a transforming cablepassing hole and filled with a liquid cooling means; a superconductingtransformer housed in the transformer housing in a state that thesuperconducting transformer is immersed in the cooling means; a tapchanger housing having a tap changing cable passing hole andvacuum-sealed form outside; a power tap changer housed in the vacuum tapchanger housing; a cable linking pipe vacuum-sealed from the transformerhousing and the tap changer housing and linking between the transformingcable passing hole and the tap changing passing hole in order that atransformer winding tap cable connecting the superconducting transformerand the power tap changer can pass through.

DETAILED DESCRIPTION

Below, embodiments of the present invention will be described in detailwith reference to the annexed drawings.

Referring to FIG. 1, a superconducting power transforming apparatus 100includes a transformer housing 10, a superconducting transformer 30, atap changer housing 20, a power tap changer 40 and a cable linking pipe50.

The superconducting transformer 30 comprises a primary winding connectedto a power supply and a secondary winding connected to a load, and usesa superconductor. Here, as an example, a high temperature superconductor(HTS) is used as the superconducting transformer 30 of the presentinvention.

The transformer housing 10 has a cylindrical shape in order to house thesuperconducting transformer 30 in. Also, the transforming cable passinghole 11 where the transformer winding tap cable 60 passes is formed onthe one side of the transformer housing 10. In this embodiment of thepresent invention, as shown in FIG. 1, the transforming cable passinghole 11 is formed at the lower part of the transformer housing 10 as anexample, and the transforming cable passing hole 11 may be formed at theupper part or the central part according to the position of thetransformer winding tap cable 60 connecting the superconductingtransformer 30 and the power tap changer 40.

Also, the inner of the transformer housing 10 is filled with a liquidcooling means for maintaining the extremely low temperature during theoperation of the superconducting transformer 30. Here, in thisembodiment of the present invention, a liquid cooling means filled inthe transformer housing 10 are provided with liquid nitrogen as anexample, and another cooling means enabling the superconductingtransformer 30 to operate may be applied.

Meanwhile, the power tap changer 40 changes the tap connection of thewinding of the superconducting transformer 30 for enabling voltageregulation of the output from the superconducting transformer 30irrespective of fluctuations in load. In this embodiment of the presentinvention, as an example, an on-load tap changer (OLTC) changing the tapconnection of the winding during the superconducting transformer 30 isused as the power tap changer 40, and a non-load tap changer may beused.

The tap changer housing 20 has a cylindrical shape in order to house thepower tap changer 40 in. And, the tap changing cable passing hole 21where the transformer winding tap cable 60 passes is formed on the oneside of the tap changer housing 20. Here, the tap changing cable passinghole 21 formed on the tap changer housing 20 is formed at the positioncorresponding to the transforming cable passing hole 11 in order thatthe cable linking pipe links the transforming cable passing hole 11 withthe tap changing cable passing hole 21.

Also, the insulation environment is made up in the inner of the tapchanger housing 20. In this embodiment of the present invention, theinner of the tap changer housing 20 is maintained in vacuum as anexample. By means of maintaining the inner of the tap changer housing 20vacuum, it is possible to make up the low temperature environment aswell as the insulation environment.

Here, in order to maintain the insulation environment in the inner ofthe tap changer housing 20, the insulating oil for cooling the power tapchanger 40 may be filled in the tap changer housing 20. And, it isdesirable to use the material which has a high flashing point, a lowfreezing point, a high fluidity, a high specific heat, and which doesn'tform the extract or isn't oxidized at a low temperature.

The cable linking pipe 50 links the transforming cable passing hole 11of the transformer housing 10 with the tap changing cable passing hole21 of the tap changer housing 20, in order that the transformer windingtap cable 60 connecting superconducting transformer 30 and the power tapchanger 40 can pass through.

Here, the cable linking pipe 50 of the present invention is vacuumsealed from the transformer housing 10 and the tap changer housing 20.As above, it is possible to guarantee stable operation of asuperconducting transformer which works at an extremely low temperatureand a power tap changer such as On-Load Tap Changer which works at lowtemperature, by means of spatial separation of the inner of thetransformer housing 10 which is at an extremely low temperature and theinner of the tap changer housing 20 which is at low temperature.

Hereafter, a coupling constitution of a transformer housing 10, a cablelinking pipe 50 and a tap changer housing 20 according to the presentinvention is explained in detail with reference to FIGS. 2 and 3.

A transforming coupling part 12, 13 for being coupled with the cablelinking pipe 50 is provided on the transforming cable passing hole 11 ofthe transformer housing 10. Referring to FIG. 2, the transformingcoupling part 12, 13 may comprise a first extended pipe part 13 extendedoutward from the transforming cable passing hole 11 of the transformerhousing 10, and a first coupling skirt part 12 extended outward in theradial direction from the end part of the first extended pipe part 12.

Also, a tap changing coupling part 22, 23 for being coupled with thecable linking pipe 50 is provided on the tap changing cable passing hole21 of the tap changer housing 20, corresponding to the shape of thetransforming coupling part 12, 13 of the transformer housing 10.Referring to FIG. 2, the tap changing coupling part 22, 23 may comprisea second extended pipe part 23 extended outward from the tap changingcable passing hole 21 of the tap changer housing 20 and a secondcoupling skirt part 22 extended outward in the radial direction from theend part of the second extended pipe part 23.

The cable linking pipe 50 may comprise a cylindrical linking pipe mainbody 51, a transforming connecting part 52 and a tap changing connectingpart 53. The transforming connecting part 52 is provided on the one sideof the linking pipe main body 51 and sealingly coupled with thetransforming coupling part 12, 13 of the transformer housing 10. Here,the transforming connecting part 52 is extended outward in the radialdirection from the one side end part of the linking pipe main body 51 inorder to be coupled with the first coupling skirt part 12 of thetransforming coupling part 12, 13.

Also, the tap changing connecting part 53 is provided on the other sideof the linking pipe main body 51 and sealingly coupled with the tapchanging coupling part 22, 23 of the tap changer housing 20. Here, thetap changing connecting part 53, corresponding to the shape of thetransforming connecting part 52, is extended outward in the radialdirection from the other side end part of the linking pipe main body 51in order to be coupled with the second coupling skirt part 22 of the tapchanging coupling part 22, 23.

Here, as shown in FIGS. 2 and 3, the superconducting power transformingapparatus according to the present invention may comprise a transformingsealing wall 54 and a tap changing sealing wall 55.

A transforming sealing wall 54 is installed between the transformingcoupling part 12, 13 and the transforming connecting part 52, and sealsthe transformer housing 10 and the cable linking pipe 50. Here, aplurality of a first cable passing holes 54 a which the transformerwinding tap cable 60 pass through is formed on the transforming sealingwall 54.

And, a tap changing sealing wall 55 is installed between the tapchanging coupling part 22, 23 and the tap changing connecting part 53,and seals the tap changer housing 20 and the cable linking pipe 50.Here, a plurality of a second cable passing holes 55 a which thetransformer winding tap cable 60 pass through is formed on the tapchanging sealing wall 55, in the same manner of the transforming sealingwall 54.

According to the above constitution, the transforming coupling part 12,13 and the transforming connecting part 52 are coupled by bolts in thestate that the transforming sealing wall 54 is installed between thetransforming coupling part 12, 13 and the transforming connecting part52. Also, the tap changing coupling part 22, 23 and the tap changingconnecting part 53 are coupled by bolts in the state that the tapchanging sealing wall 55 is installed between the tap changing couplingpart 22, 23 and the tap changing connecting part 53. So, the transformerhousing 10, the cable linking pipe 50 and the tap changer housing 20 aremutually separated spatially.

Here, as shown in FIG. 3, the plurality of the first cable passing holes54 a formed on the transforming sealing wall 54 are spaced apart fromeach other at a predetermined distance in order to prevent an insulationbreakdown between the transformer winding tap cables 60 passing througheach of the first cable passing holes 54 a. Also, the plurality of thesecond cable passing holes 55 a formed on the tap changing sealing wall55 are spaced apart from each other at a predetermined distance in orderto prevent an insulation breakdown between the transformer winding tapcables 60 passing through each of the second cable passing holes 55 a.

And, the transforming sealing wall 54 and the tap changing sealing wall55 may be provided with epoxy resin which is effective in keeping thecable linking pipe 50 vacuous, and the first cable passing holes 54 aand the second cable passing holes 55 a are coated in epoxy resin forkeeping them sealed in state that the transformer winding tap cables 60pass through the first cable passing holes 54 a of the transformingsealing wall 54 and the second cable passing holes 55 a of the tapchanging sealing wall 55.

In the state after the cable linking pipe 50 being coupled as above, thelinking pipe main body 51 may be made vacuous by means of a vacuum pumpconnecting to the pump connection part formed on the cable linking pipe50 and removing air in the linking pipe main body 51 of the cablelinking pipe 50.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

INDUSTRIAL APPLICABILITY

The present invention relates to a superconducting power transformingapparatus, it can be applied to the field of the power transformingapparatus using the superconductor by guaranteeing stable operation of asuperconducting transformer which works at an extremely low temperatureand a power tap changer as like On-Load Tap Changer which works at lowtemperature.

1. A superconducting power transforming apparatus comprising; atransformer housing having a transforming cable passing hole and filledwith a liquid cooling means; a superconducting transformer housed in thetransformer housing in a state that the superconducting transformer isimmersed in the liquid cooling means; a tap changer housing having a tapchanging cable passing hole and vacuum-sealed from outside; a power tapchanger housed in the vacuum tap changer housing; and a cable linkingpipe vacuum-sealed from the transformer housing and the tap changerhousing, and linking the transforming cable passing hole with the tapchanging passing hole in order that a transformer winding tap cableconnecting the superconducting transformer and the power tap changerpasses through.
 2. The superconducting power transforming apparatusaccording to claim 1, wherein the superconducting transformer isprovided with a type of a high temperature superconducting transformer;and wherein the liquid cooling means are provided with liquid nitrogen.3. The superconducting power transforming apparatus according to claim2, wherein the power tap changer is provided with a type of an On-LoadTab Changer (OLCT).
 4. The superconducting power transforming apparatusaccording to claim 3, further comprising; a transforming coupling partcoupled with the cable linking pipe and provided on the transformingcable passing hole of the transformer housing; and a tap changingcoupling part coupled with the cable linking pipe and provided on thetap changing cable passing hole of the tap changer housing; wherein thecable linking pipe comprises a cylindrical linking pipe main body, atransforming connecting part provided on the one side of the linkingpipe main body and sealingly coupled with the transforming couplingpart, and a tap changing connecting part provided on the other side ofthe linking pipe main body and sealingly coupled with the tap changingcoupling part.
 5. The superconducting power transforming apparatusaccording to claim 4, further comprising; a transforming sealing wallinstalled between the transforming coupling part and the transformingconnecting part, sealing the transformer housing and the cable linkingpipe and having a plurality of a first cable passing holes where thetransformer winding tap cable passes; and a tap changing sealing wallinstalled between the tap changing coupling part and the tap changingconnecting part, sealing the tap changer housing and the cable linkingpipe, and having a plurality of a second cable passing holes where thetransformer winding tap cable passes.
 6. The superconducting powertransforming apparatus according to claim 5, wherein the plurality ofthe first cable passing holes is spaced apart from each other at apredetermined distance in order to prevent an insulation breakdownbetween the transformer winding tap cables passing through each of thefirst cable passing holes; and wherein the plurality of the second cablepassing holes is spaced apart from each other at a predetermineddistance in order to prevent an insulation breakdown between thetransformer winding tap cables passing through each of the second cablepassing holes.
 7. The superconducting power transforming apparatusaccording to claim 5, wherein the transforming sealing wall and the tapchanging sealing wall are provided with epoxy resin.
 8. Thesuperconducting power transforming apparatus according to claim 5,wherein the cable linking pipe further comprises a pump connecting partconnected with a vacuum pump for making an inner of the linking pipemain body vacuous.
 9. A superconducting power transforming apparatuscomprising; a transformer housing having a transforming cable passinghole and filled with a liquid cooling means; a superconductingtransformer housed in the transformer housing in a state that thesuperconducting transformer is immersed in the cooling means; a tapchanger housing having a tap changer cable passing hole and filled witha insulating oil; a power tap changer housed in the tap changer housingin a state that the power tap changer is immersed in the insulating oil;and a cable linking pipe vacuum-sealed from the transformer housing andthe tap changer housing and linking the transforming cable passing holewith the tap changing passing hole in order that a transformer windingtap cable connecting the superconducting transformer and the power tapchanger can pass through.
 10. The superconducting power transformingapparatus according to claim 9, wherein the superconducting transformeris provided with a type of a high temperature superconductingtransformer; and wherein the liquid cooling means are provided withliquid nitrogen.
 11. The superconducting power transforming apparatusaccording to claim 10, wherein the power tap changer is provided with atype of an On-Load Tab Changer (OLCT).
 12. The superconducting powertransforming apparatus according to claim 10, further comprising; atransforming coupling part coupled with the cable linking pipe andprovided on the transforming cable passing hole of the transformerhousing; and a tap changing coupling part coupled with the cable linkingpipe and provided on the tap changing cable passing hole of the tapchanger housing; wherein the cable linking pipe comprises a cylindricallinking pipe main body, a transforming connecting part provided on theone side of the linking pipe main body and sealingly coupled with thetransforming coupling part, and a tap changing connecting part providedon the other side of the linking pipe main body and sealingly coupledwith the tap changing coupling part.
 13. The superconducting powertransforming apparatus according to claim 12, further comprising; atransforming sealing wall installed between the transforming couplingpart and the transforming connecting part, sealing the transformerhousing and the cable linking pipe and having a plurality of a firstcable passing holes where the transformer winding tap cable passes; anda tap changing sealing wall installed between the tap changing couplingpart and the tap changing connecting part, sealing the tap changerhousing and the cable linking pipe, and having a plurality of a secondcable passing holes where the transformer winding tap cable passes. 14.The superconducting power transforming apparatus according to claim 13,wherein the plurality of the first cable passing holes is spaced apartfrom each other at a predetermined distance in order to prevent aninsulation breakdown between the transformer winding tap cables passingthrough each of the first cable passing holes; and wherein the pluralityof the second cable passing holes is spaced apart from each other at apredetermined distance in order to prevent an insulation breakdownbetween the transformer winding tap cables passing through each of thesecond cable passing holes.
 15. The superconducting power transformingapparatus according to claim 13, wherein the transforming sealing walland the tap changing sealing wall are provided with epoxy resin.
 16. Thesuperconducting power transforming apparatus according to claim 13,wherein the cable linking pipe further comprises a pump connecting partconnected with a vacuum pump for making an inner of the linking pipemain body vacuous.